Neither the tube or a velocity stack is a cure for carb spitting. The stack only relocates it. Since a two stroke breathes through the bottom of the engine or side of the cylinder, and inducts through the bottom of the engine or side of the cylinder, they have a tendency to push a little fuel out the induction side on alternate strokes. Once you understand how a two stroke functions, and also understand the bottom end pressure pulse that impacts carbs and reeds, making them work, you understand why a little gas exiting the carb is nothing to be excited about. If you used an air filter, and I can pretty much assure you do not because nobody does, you'd find that the filter would remain well oiled and capture more dirt because of the little bit of gas that exits the carb.

better to prepare for the inevitable. Fuel proof the firewall, and inside the engine box if a carb is inside of it. You did this all the time with glow engines, why forget it now? Provide a little venting for the engine box to permit air to help dry out any gas that gets in there. If there is a lot of gas, and that's subjective, look for a leaking reed and fix it. Ignorance is not bliss. Ever wonder why all that brown crud was all over the front of your glow engines? It's because fuel came out of the carb in flight........